ENVIRONMENTAL REACTIVITY CHARACTERISTICS OF COPPER-OXIDE SUPERCONDUCTORS

Although it is known that some of the high-T(c) phases react rapidly w ith water, CO2, CO, and acids, no systematic comparison of the relativ e reactivities of the various cuprate superconductors is available. In this letter, x-ray powder diffraction, scanning electron microscopy, x-ray photoemission spectroscopy, and electrochemical measurements are utilized to establish a comprehensive comparison of the intrinsic rea ctivity characteristics of the common copper-oxide superconductors. Co nsequently, the following reactivity scale has been determined: YBa2Cu 3O7 > Tl2Ba2Ca2Cu3O10 > Bi2Sr2Cu2O8 greater-than-or-equal-to La1.85Sr0 .15CuO4 > Nd1.85Ce0.15CuO4 > Nd1.85Th0.15CuO4.